US3477183A

US3477183A - Low profile rigid frame metal building

Info

Publication number: US3477183A
Application number: US655489A
Authority: US
Inventors: David R Graham
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-07-24
Filing date: 1967-07-24
Publication date: 1969-11-11
Anticipated expiration: 1986-11-11

Description

Nov. 11, 1969 b. RpGRAHAM LOW PROFILE RIGID FRAME METAL BUILDING 3 Sheets-Sheet 1 Filed July 24, 1967 INVENTOR.

5 W m A d. m0 r r G Mr R 7 w 9 a w 9 V Nov. 11; 1969 D. R. GRAHAM 3,477,183

LOW PROFILE RIGID FRAME METAL BUILDING Filed July 24, 1967 3 Sheets-Shed z INVENTORQ EM 5 flay/a A. Graham YOU/J97 Tho/20,0500

. ATTORNEYS Nov. 11, 19 69 GRAHAM 3,477,183

LOW PROFILE" RIGID FRAME METAL BUILDING Filed July 24, 1967 s Shets-Sheet s INVENTOR.

08 W0 H Graham YOU/)9 Thompson ATTORNEYS United States Patent US. C]. 52-73 4 Claims ABSTRACT OF THE DISCLOSURE A low profile rigid frame metal building of very wide span is characterized by a column pinned to the rafter intermediate the length of the rafter and guy cables interconnecting the upper end of the column and spaced points along the rafter located in rigid regions of the rafter, a fluid dashpot interconnects the upper free ends of opposed pairs of rafters, across the center line of the building, to damp relative movement of the free ends, a sliding connection between the free ends also prevents them from moving out of their common plane, and a ridge cap is pivotally carried by the upper ends of the rafters.

The present invention relates to low profile rigid frame metal buildings, of the type in which rafters inclined at a relatively small pitch angle are rigid at their lower ends with the columns adjacent a side wall of the build ing. Such constructions are useful in metal buildings having a ridge along the center line of the building, with pairs of rafters disposed in common vertical planes and their upper ends adjacent each other. Such construction is also useful in metal buildings that are open on one side such as airplane hangars or other cantilevered buildings, in which case the upper ends of the rafters are at one side of the building.

Among the objects of the invention are the provision of a low profile rigid frame metal building which will have a maximum of useable interior space, which will so distribute the bending moments in the columns and rafters that less steel will be required in its construction, that will be free from destructive rhythmic motion under the influence of wind or other unequal loads, that will enable the construction of buildings of greatly increased span between columns, that will accommodate to snow load, and that will be relatively easy and inexpensive to manufacture and erect and rugged and durable in use.

Other objects and advantages of the present invention will become apparent from a consideration of the following description, taken in connection with the accompanying drawings, in which:

FIG. 1 is a somewhat diagrammatic view in cross section of the frame of a metal building according to the present invention;

FIG. 2 is a moment diagram showing the magnitude and distribution of the bending forces in a ratfer and rigidly attached column of a building according to the invention;

FIG. 3 is an enlarged fragmentary perspective view of the connection between the upper adjacent ends of opposed rafters, that is, in the region of the center of FIG. 1;

FIG. 4 is a top plan view, with parts broken away, of the structure of FIG. 3;

FIG. 5 is a side elevational view of the structure of FIGS. 3 and 4 showing the mounting of the ridge cap;

FIG. 6 is an enlarged fragmentary perspective view of the pin connection between a rafter and the column which is intermediate the length of the rafter;

FIG. 7 is a side elevational view, with parts broken away, of the structure of FIG. 6;

FIG. 8 is a fragmentary perspective view of the assembly of rafters and purlins;

FIG. 9 is an enlarged fragmentary elevational cross sectional view of the structure of FIG. 8, looking endwise of a rafter; and

FIG. 10 is a still further enlarged fragmentary perspective view showing an expansion joint between purlin ends.

Referring now to the drawings in greater detail, there is shown a low profile rigid frame metal building indicated generally at 1 comprising a plurality of first columns 3 disposed in vertical files at opposite sides of the building. For simplicity, it will be understood that only one set of columns 3 and the associated building structure are shown in FIG. 1, it being understood that the structure of FIG. 1 is duplicated as many times as desired, on opposite sides of the plane of FIG. 1 thereby to provide a metal building of any desired length. Inclined ratfers 5 in the form of steel box girders are provided, which are rigidly secured at their lower ends to the upper ends of columns 3 and are relatively free or non-load bearing at their upper ends. Second columns 7, which are of a height such that their upper ends extend substantial distances above rafters 5, are provided which are disposed intermediate the length of rafters 5 but closer to columns 3, and are inclined upwardly in the direction of columns 3.

Pins 9 interconnect rafters 5 and columns 7 for relative vertical swinging movement. In the illustrated embodiment, columns 7 are cut and rafters 5 pass through them, the pins 9 being carried by columns 7 and passing through rafters 5. Guy cables 11 extend from the top of second columns 7 and are secured to rigid portions of rafters 5 at points that are spaced from each other and spaced substantial distances from columns 7. Preferably, the guy cables 11 extend in both horizontal directions from columns 7.

The upper ends 13 of the rafters 5 are disposed adjacent each other in the embodiment shown in FIG. 1. It will be understood, however, that the portion of the building on either side of its longitudinal center line is usable as a cantilever type building.

The rafters 5 carry horizontal purlins 15 that extend perpendicular to and are secured to the upper sides of rafters 5. Braces 17 extend diagonally between purlins 15 and lower portions of rafters 5. Certain contiguous ends of purlins 15 are provided with slide joints 19 so as to accommodate thermal expansion and contraction and other influences that cause the ends of purlins 15 to move relative to each other.

Of course, purlins 15 support the usual roof sheets (not shown).

The ends 13 of each pair of opposed rafters 5 are interconnected by a hydraulic dash pot 21, including a cylinder 23 that is pivotally secured for vertical swinging movement on and relative to one end 13 of one rafter 5, While its corresponding piston and piston rod 25 are pivotally mounted for vertical swinging movement on and relative to the other end 13 of the other rafter 5 of the pair. The axis of dash pot 21 is substantially horizontal. The cylinder 23 of dash pot 21 is filled with a hydraulic liquid on opposite sides of piston 25, and piston 25 provides for passage of the liquid from one side to the other of piston 25, thereby to damp movement of the ends 13 in both horizontal directions in their common plane. Preferably, piston 25 has one-way valve means (not shown) therein, to permit free collapse of dash pot 21 but yieldingly to resist extension of dash pot 21. Of course, the one-way valve means could be reversed so as to act the other way, or eliminated so that movement in both directions was yieldingly resisted.

Shear plates 27 are also provided, which are disposed in vertical planes and secured to opposite sides of one of the ends 13 and slidably received on opposite sides of the other end 13 in guides 29. Shear plates 27 thus prevent movement of ends 13 relative to each other out of their common plane, that is, parallel to the planes of the building, While at the same time permitting movement of ends 13 toward and away from each other parallel to the axis of dash pot 21. Shear plates 27 and their guides 29 also maintain ends 13 at a common horizontal level so as to avoid differential vertical displacement of ends 13.

A ridge cap 31 is disposed above and closes the gap between ends 13 and extends full length of the building. Ridge cap 31 is carried by brackets 33 on each of ends 13, as seen in FIG. 5. Struts 35 are pivotally interconnected at 37 to brackets 33 and at 39 to ridge cap 31, thereby to support ridge cap 31 on brackets 33 and at the same time to permit movement of ends 13 relative to each other and to ridge cap 31. Screens 41 close the gap between brackets 33 or the adjacent purlin 15 on the one hand, and ridge cap 31 on the other hand. Ridge cap 31 thus renders the ridge of the building weather tight while at the same time providing ventilation for the interior of the building.

FIG. 2 shows the moment diagram for a building according to the present invention. It will be apparent from FIG. 2 that the bending moments are greatest adjacent the haunch between the columns 3 and the rafters 5, as is usual in rigid frame buildings of this type. It is for this reason, of course, that the columns 3 are wider adjacent their upper ends than adjacent their lower ends. Similarly, the moment diagram of FIG. 2 shows that a portion of the weight of rafters 5 is borne by the pin 9, and that bending stresses of course tend to concentrate along the rafter at the points of connection of the guy cables 11. It will also be apparent from the moment diagram of FIG. 2 that rafter 5 could be in sections with pivotal joints disposed at any or all of the points where the bending moment is zero; but it is preferred that rafter 5 be rigid along its full length. Finally, it will be apparent from the moment diagram of FIG. 2 that a construction has been achieved in which the bending moments are so distributed that the rafters 5 can be made of desirably lightweight and hence inexpensive construction, with a consequent reduction in the weight and cost of the building. At the same time, the free or upper ends of the rafters 5 can be non-load bearing and movable relative to each other, thanks to the special arrangements shown in FIGS. 3 to 5.

From a consideration of the foregoing disclosure, therefore, it will be evident that all of the initially recited objects of the present invention have been achieved.

What is claimed is:

1. A support for a portion of a low profile metal building comprising an inclined rafter, a first column rigid with the lower end of the rafter, a second column intermediate the ends of the rafter, means interconnecting the rafter and the second column for relative vertical swinging movement, the portions of the rafter on opposite sides of the second column being rigid with each other, the second column extending a substantial distance above the rafter, first guy means interconnecting the second column a substantial distance above the rafter with a plurality of spaced points intermediate the length of the rafter a substantial distance from the second column and on the side of the second column opposite the first column, and second guy means anchoring the second column a substantial distance above the rafter to a point on the same side of the second column as the first column, the rafter being substantially rigid throughout its length.

2. A support as claimed in claim 1, there being a pair of opposed and oppositely inclined said rafters that lie in a common vertical plane and whose upper ends are disposed adjacent each other to define a ridge for the building, and means interconnecting said upper ends of the rafters and preventing substantial movement of the rafter ends relative to each other out of said plane while permitting substantial movement of said rafter ends relative to each other in said plane, said preventing means comprising guide means slidably interconnecting said rafter ends on opposite sides of at least one of said rafter ends.

3. A support as claimed in claim 1, there being a pair of opposed and oppositely inclined said rafters that lie in a common vertical plane and whose upper ends are disposed adjacent each other to define a ridge for the building, a ridge cap for the building, means pivotally interconnecting the ridge cap with one of said adjacent rafter ends for relative vertical swinging movement about a first horizontal axis, and means pivotally interconnecting the ridge cap with the other of said adjacent rafter ends for relative vertical swinging movement about a second horizontal axis spaced from and parallel to said first axis.

4. A support as claimed in claim 1, said second guy means being anchored to said support adjacent the junction of said first column and said inclined rafter.

References Cited UNITED STATES PATENTS 1,419,868 6/1922 Levitan 52-83 1,689,131 10/1928 Goodwin 52-1 2,053,226 9/1936 Ruge 52167 3,138,828 6/1964 Greenbie 52-90 FRANK L. ABBOTT, Primary Examiner S. D. BURKE, III, Assistant Examiner US. Cl. X.R. 5290, 94, 146, 167